The touch screen LCD display developed quickly, and it has already evolved into a mainstream flat panel display. The manufacturing process of a LCD display mainly includes producing a color filter (CF) substrate including forming a black matrix (BM), a color filter film, a planarization layer and a common electrode on a substrate in this order; producing an array substrate; performing alignment treatment for the array substrate and the color filter substrate, injecting liquid crystal after assembling of the array substrate and the color filter substrate so as to form a liquid crystal cell; assembling polarizers, backlight and driving circuit so as to form a module with separate standard external interface. As shown in FIG. 1, in a process of producing a color filter substrate, a layer of black matrix 12 is firstly produced on the substrate 11 for preventing the color blending of adjacent sub-pixels in respective pixel. However, this black matrix 12 induces a poor surface flatness in the subsequent process for producing the color filter film (color paste), that is, Red (R), Green (G) and Blue (B) color pastes, which makes it difficult to make the common electrode 14 thereon. As a result, a planarization layer 13 is added for planarization so as to prepare for the common electrode 14.
Generally, the touch screen is manufacturing by adding a sensing layer for determining touch points on the liquid crystal panel. For capacitive touch screen, the capacitive sensor is usually manufactured on the rear surface of a substrate of color filter substrate. As shown in FIG. 2, the capacitive sensor comprises an upper and lower layer made of transparent conductive film 15 (Indium Tin Oxides, ITO) and a layer of insulating film 16 sandwiched between two layers of transparent conductive film 15. The upper and lower layer made of transparent conductive film 15 serve as an upper plate 17 and a lower plate 18 of the capacitor, respectively. When the touch screen is touched, the capacitance of the touch point changes, which induces variation of either the current or pulse signal in transverse and longitudinal directions, which is detected by the sensors in transverse and longitudinal directions, thus determining coordinates of the touch point in transverse and longitudinal directions and enabling addressing.
During manufacturing process of above touch screen, there are some issues such as the need to produce a plurality of layers and associated complex processing, which makes it difficult to reduce the cost of the touch screen and make the touch screen thin and light weight.